Hydraulic work device



Feb. 17, 1942. C COTNER 2,273,315

HYDRAULIC WORK DEVICE Original Filed March 10, 1938 5 Sheets-Sheet l INVENTOR.

Jofia C. L'otm A TTORNE '1.

Feb. 17, 1942.

J. c. COTNER 2,273,315

HYDRAULIC WORK DEVICE Original Filed March 10, 1938 5 Sheets-Sheet 2 Jofia C. Cotaezr BY 0644 Wm ATTORNEY.

Feb. 17, 1942. J Q CQTNER 2,273,315

HYDRAULIC WORK DEVICE Original Filed March 10, 1938 3 Sheets-Sheet 3 INVENTOR.

Jail! 6. 60M

%a +ma fii TORNEY I Patented Feb. 17, 1942 2,213,315 m'mmouc wonx navrca John C. Cotner, Logansport, Ind., aasignor to Lolansport Machine, Inc.

Original application March 10, 1938, Serial No.

1939, Serial No. 266,021

BClaims.

This application is a division of my application Serial #195,093 flled on March 10, 1938, and entitled Fluid systems.

My invention, in general, relates to hydraulic machines and actuating means therefor.

An object of my invention is the provision of a fluid system having two fluid portions, including hydraulic operated devices. taken in combination with a fluid pump for delivering a fluid to each of said fluid portion to actuate the hydraulic operated devices.

A further object of my invention is the provision of a fluid system having two fluid portion including hydraulic operated devices, taken in combination with a fluid pump and control means for alternately delivering a fluid to each of said fluid portions for actuating the hydraulic operated devices.

A still further object of my invention is the provision of a fluid system having a high pressure fluid portion and a low pressure fluid portion connected in communication with hydraulic operated devices, taken in combination with a fluid pump and a rotating mass driven by power means and control means for alternately connecting the fluid pump in communication with the two fluid portions of the fluid system, wherein the power means is of suflicient capacity to drive the fluid pump when the fluid pump is connected in communication with the low pressure fluid portion, but of insuflicient capacity to drive continually the fluid pump when the fluid pump is connected in communication with the high pressure fluid portion, and whereby the rotating mass is adapted to assist the power means when slowing down in speed, to drive the fluid pump when the fluid pump is connected in communication with the high pressure fluid portion and thus produce an increase in pressure to that which the slowing down power means could produce alone, and whereby the control means is actuated in response to the fluid pressure in the high pressure fluid portion to connect the fluid pump in communication with the low pressure fluid portion and allow the power means to resume its speed.

A further object of my invention is the provision of power means to drive a fluid pump wherein the power means is sufiicient to drive the fluid pump under relatively low pressures but insufficient to drive the fluid pump under relatively high pressures, taken in combination with a rotating mass which assists the power means when slowing down in speed to drive the fluid pump and thereby producing a higher pressure than Divided and this application April 4,

that which the power means could produce alone.

It is also an object of my invention to provide for disconnecting the fluid pump from a high pressure portion of a system and connecting it in communication with a low pressure portion of a fluid system when the power means which drives the fluid pump is slowed down by reason 01' the insuflicient capacity to drive continually the fluid pump when connected in communication with the high pressure portion of the fluid system.

. It is a still further object of my invention to provide for disconnecting a fluid pump from a high pressure portion of a fluid system and conmeeting the pump in communication with a low pressure fluid portion of the fluid system, in accordance with the pressure of the fluid in the high pressure fluid portion of the fluid system.

Another object of my invention is to provide for alternately and automatically connecting a fluid pump in communication with a high pressure fluid portion and with a low pressure fluid port-ion of a fluid system to operate hydraulic operated devices which are connected in communication with the fluid system.

A still further object of my invention is the provision of operating a fluid system employing hydraulic operated devices in a cyclic manner,

wherein during the first part of the cycle, a fluid pump is connected in communication with a low pressure fluid portion of the system and is driven by a motor which also drives a rotating mass, and wherein during the second part of the cycle, the fluid pump is connected in communication with a high pressure fluid portion of the fluid system and is driven by the said motor which is of insuflicient capacity t drive continuously the fluid pump under high pressure conditions which means that the rotating mass under this condition of the slowing down of the motor, supplies energy to the fluid pump to assist the motor temporarily in producing a higher pressure than that which the motor could produce alone, thereby completing the second part of the cycle, at which time the fluid pump is again reconnected in communication with the low pressure fluid portion and allows the motor and the rotating mass to again regain its speed preparatory to another cyclic operation.

Another object of my invention is to provide for electrically operating control means which governs the flow of the fluid in a fluid system employing hydraulic operated devices.

Another object of my invention is to provide for hydrostatically operating the control means which govems'the flow of the fluid in a fluid system employing hydraulic operated devices, wherein the entire fluid system assembly is mounted in a unitary housing having an anvil and a work cylinder support constructed as a complete operative unit.

Other objects and a fuller understanding may be had by referring to the following description and claims taken in combination with the accompanying drawings in which:

Figure 1 represents a diagrammatic illustration of a fluid system employing hydraulic operated devices constructed in accordance with the features of my invention;

Figure 2 shows my invention assembled in a housing having an anvil and a work cylinder support, and

Figure 3 shows a modifled arrangement of my invention shown in Figure 2.

With reference to Figure 1, my fluid system comprises an assembled pumping unit I0, a double acting work cylinder 24, a four-way control valve 45, a high pressure relief valve 63, a low pressure relief valve 16, a fluid container 61, and a fluid pressure responsive device 30 for electrically actuating, in one direction, the four-way control valve.

The assembled pumping unit I comprises a fluid pump II, a motor I2, and a fly-wheel I3 suitably mounted upon a base plate l4. Positioned on opposite sides of the fly-wheel I3 are two pedestals l5 and I6 which support the shaft upon which the fly-wheel I3 is mounted. In order that the motor may be removed without disturbing the other associated parts of the assembled pumping unit, there is provided a suitable coupling I1 between the motor I2 and the pedestal l5. Similarly, in order that the fluid pump may be removed without disturbing the other associated parts of the pumping unit, there is provided a suitable coupling I8 between the fluid pump II and the pedestal I6.

While not shown, the motor I2 is adapted to be connected to any suitable supply source by means of the usual switches and starting boxes. The fluid pump II is adapted to deliver fluid to the double-acting work cylinder 24. As illustrated, the double-acting work cylinder 24 comof the piston 29 through a low pressure port 36. While not shown, the entire double acting work cylinder may be suitably mounted to a support by means of bolts, extending through the openings 40 in the cylinder base 21.

The function of the four-way control valve 45 is to control the flow of the fluid to the double acting work cylinder 24. As shown, the four-way control valve comprises a valve casing 46, a valve piston rod 41, an electro-magnet 48 for actuating the valve piston rod in one direction, and a hand controlled lever 50 for actuating the valve piston rod 41 in the other direction. The electromagnet 43 may be suitably mounted to the right hand end of the valve casing 46, such as for assembling by means of the supporting members 49. The electro-magnet 48 is arranged when energized to actuate the valve piston rod 41 to the right and connect the fluid pump I I in communication with the underneath side of the piston 29 in the double acting work cylinder 24. The hand control lever 50 may be suitably pivoted to the left hand end of the valve casing 46 by means of the linkage members 5|, so that when the upper end of the hand controlled lever 50 is actuated to the right, the valve piston rod 41 is moved to the leftand connects the fluid pump II in communication with the top side of the piston 29 in the double acting work cylinder 24.

Integrally formed with the valve piston rod 41 are two spaced valve pistons 56 and 51 which snugly, but freely, reciprocate within the longitudinal bore of the valve casing 46. The purpose prises generally a cylinder wall 25, a cylinder head 26, and a cylinder base 21. To facilitate the construction of the double acting work cylinder, the cylinder head and the cylinder base are rigidly clamped against the ends of the cylinder wall 25 by means of the screw bolts 26. Mounted within the cylinder wall 25 is a piston 29 having suitable piston rings 30 to make a good fluid. tight connection. Attached to the piston 29 by means of a piston nut 32 is a piston rod 3| which reciprocally moves through the cylinder base 21. In order to afford a good fluid tight connection, there is placed around the piston rod 3I suitable packing 35 which is held in position by means of a packing flange 33 that may be bolted or otherwise connected to the cylinder base 21 by means of the cap screws 34. The lower end of the piston rod 3| is threaded to receive the uppermost threaded end of a stamping or work tool 36, which is reciprocally actuated with reference to the work block 39.

The double acting work cylinder is actuated in both directions by means of fluid delivered from the fluid pump II. Upon the downward stroke of the piston 29, fluid is delivered on top of the piston through means of a high pressure port 21, and upon the upward stroke of the piston 29, fluid is delivered on the underneath side of the two spaced valve pistons 56 and 51 is to control the flow of the fluid through the four-way control valve 45. In the position illustrated, the fluid from the pump II is delivered to the bore of the valve casing 46 through a supply port 52, after which thefluid is delivered from the valve casing 46 through a port 54, and thence'through the pipes I06 and III to the underneath side of the piston 29 in the double acting work cylinder 24. The upper movement of the piston 29 forces the fluid, which is above the piston, out of the double acting work cylinder through the port 31 and thence through the pipe I05 to a port 53, after which the fluid flows through an exhaust duct.58 in the lower most portion of the valve casing 42, and into an exhaust pipe H0, which is connected to an exhaust port in the right hand end of the valve casing 46, and which delivers the exhaust fluid to the fluid container 81. When the valve piston rod 41 is actuated to the left in the reverse position to that shown in the 5 drawing, the valve piston 56 is now to the left of the port 53 and the valve piston 51 is to the left of the port 54, and the fluid delivered from the pump II enters the supply port 52 as before but by reason of the shifting of the valve piston 0 rod 41, the fluid is directed out of the valve casing 46 through the port 53 and into a pipe I05 which delivers the fluid to the upper side of the piston 29 in the double acting work cylinder. This forces the piston 29 downwardly and causes the fluid on the underneath side of the piston 29 to be forced out through the port 39 into the pipes III and I06 to the port 54 in the valve casing 46, which port 54 is now in communication with the exhaust port 55, so that the fluid upon entering the port 54 flows through the valve casing 46 and into the exhaust pipe IIO where the fluid is flnally delivered to the fluid container 61.

In the operation of the double acting work cylinder 24, it is observed that the pressure necessary to raise the piston 22 need not be very reat. This is true for the reason that there is no actual external work done in lifting the piston 29, except to overcome the resistance to the movement of the piston 29 and the piston rod 8|. However, upon the downward stroke of the piston 2!, there must be sufficient pressure to overcome not only the resistance to the movement of the piston 29 and the piston rod 3i, but also to provide sufficient force to do external work between the stamping tool It and the work block ll, such as riveting, stamping, stenciling, and other stamping operations. Accordingly, my fluid system may be characterized as having a low pressure fluid portion and having a high pressure fluid portion.

In order to maintain two .values of fluid pressure, I employ a high pressure relief valve 63 and a low pressure relief valve 1'. The construction of these two relief valves are substantially the same. The high pressure relief valve 82 will be described flrst. As illustrated, this relief valve comprises a casing 64, a differential piston ii, a spring it, and an adjustment screw It for varying the pressure of the spring 6|, and in turn, the pressure of the fluid in the high pressure fluid portion of the fluid system. The differential piston t! is constructed of a large piston portion 8 and a slightly smaller piston portion 61 spaced from the large piston portion it. The large piston portion 66 is arranged to slide into a valve port 12 and thereby control the flow of the fluid between the inlet port 1| and the outlet port 10. In the position shown, the lower most portion of the large piston 66 is positioned within the valve port 12, and, accordingly, the port 12 is closed which prevents the flow of the fluid through the high pressure relief valve 63. Under the closed position, of the relief valve 53, the downward biasing force of the spring 68 is greater than the upward differential force of the fluid tending to raise the differential piston 65. By utilizing a differential piston, as illustrated, it is only necessary to use a relatively small spring 68. This is true by reason of the fact that the spring 68 only has to be large enough to overcome the differential frce-of the fluid which is a measure of the difference in area between the large piston 6t and the somewhat smaller piston 61. The adjustment screw 69 is arranged to vary the tension of the spring 68 which in turn, governs the value of the fluid pressure, which is suflicient to raise the differential piston 55 and allow the fluid to escape through the high pressure relief valve 63. When the fluid is allowed to escape through the high pressure relief valve 63, it flows from the feed pipe lfll through the pipe I02, the high pressure relief valve Iii, and the pipe I04 into the fluid container 81. In the actual operation of my invention, I preferably set the adjustment of the spring 68 so that it requires a relatively high pressure to lift the differential piston 65 and allow fluid to escape the fluid container 81.

The low pressure relief valve 16 may be of the same construction as the high pressure relief valve 63 and as illustrated, it comprises a casing 11, a differential piston 18, a spring Ill, and an adjustment screw 8|. The differential piston 18 is arranged to control the flow of the fluid through the valve port 19. In the position shown, the differential piston 18 is urged to the left and is in the opened position which allows fluid to flow from the inlet port 82 through the valve fluid flows through the pipe 8 into the fluid container 81. The adjustment of the spring ll is such that the fluid may escape through the low pressure relief valve 1' at relatively low pressures. ApressureaI-ml!isconnectedincom-- munication with the feed pipe Ill thro h means of a pipe Ill so that the operator may observe the pressure in the fluid system.

Inasmuch as my fluid system is alternately operated between a high pressure fluid setting as determined by the high pressure relief valve '3. and a low pressure fluid setting as determined by the low pressure relief valve It, I provide a magnetic means for actuating the four-way control valve 48 to transfer the flow of the fluid from the high pressure fluid portion of the system to the low pressure fluid portion of the system. This automatic means comprises a pressure responsive device OI having an inlet fluid port 95 connected in communication with the pipe HIS, through a pipe 4. As shown, the pressure responsive device comprises a casing ti, a piston 92, and a spring l4, which opposes the pressure of the fluid against the piston 92, and a plunger 83 and an adjustment member Ill which actuates a contactor 9!. As is manifest, when the pressure of the fluid within the pressure responsive device 9. attains a pre-determined value, the plunger 93 and the adjustment member I01 are urged to the right and closes the contactor 96, which allows current to-flow from the supply conductor 91 through the contactor 98, the conductor 99, the winding of the electro-magnet 48 and back to the other supply conductor 88. The energization of the electro-magnet 48 shifts the valve piston rod 41 of the four-way control valve 45 to the right and transfers the flow of the fluid from the high pressure fluid portion to the low pressure fluid portion. The setting of the adjustment member "1 may be such as to accommodate any suitable operating condition. In actual practice, the setting of the adjustment member may be such that the value of the fluid pressure, which is sufficient to actuate the contactor 96, is below the value of the fluid pressure required to actuate the high pressure fluid relief valve 63.

In explaining the operation of my device, let it be assumed that the pump 1 I is being operated by the motor I2 and that the pump H is connected in communication with the low pressure fluid portion of the system. Under this condition, the various parts of the system are assuming the position as shown in the patent drawings. Accordingly, fluid is drawn from the fluid container 81 through a screen 88, a suction pipe I00 to the fluid pump ll, after which the fluid is propelled until it attains a sufficient value to urge the differential piston 18 of the low pressure relief valve 16 to the left. This allows the fluid to escape through the pipe H2, the low pressure relief valve 16, and the pipe H3 to the fluid container 81. Under ordinary operating conditions, I flnd that the low pressure fluid value as deterport 19, and out of the outlet port 83 where the mined by the setting of the low pressure relief to perform a riveting, stenciling, or stampingoperation. To do this, the operator places the work upon the work block 39 underneath of the work tool 36 and at the same time manually actuates the upper end of the hand controlled lever 50 to the right. Under'this condition, the fluid from the feed pipe H is caused to flow through the. four-way control valve 45 into the pipe I05 and the upper side of the piston 29. This causes the piston 29 to move downwardly and force the work tool 30 downwardly upon the work being performed, such as stamping, riveting, stenciling, or the like. When the work tool 36 engages the work being performed, there is a resistance set up opposing the further downward travel of the piston 29 at which time the fluid pressure above the piston 29 rises to a high value in order to overcome the resistance set up by the work tool performing th stamping, stenciling, or other operation. Just as soon as .the pressure begins to attain a higher valve, the motor I2, being of insuflicient capacity to provide the necessary power to drive continually the fluid pump II, tends to slow down materially. Simultaneously, with the slowing down of the motor I2, the revolving fly-wheel I3 tends to assist the further operation of the fluid pump II and thus cause the fluid pump II to produce a higher fluid pressure than it would by the driving power of the motor I2 alone. Therefore, by reason of the energy stored up in the revolving fly-wheel I3, there is produced momentarily a relatively high fluid pressure to perform considerably heavy duty. This is true because each stamping operation is substantially instantaneous and consequently the duration thereof is of a shorter period than the time it takes the motor I2 and the revolving flywheel I3 to stall.

In actual operation, I flnd that the setting of the high pressure fluid valve, as determined by the setting of the high pressure relief valve 83, may be in the neighborhood of 1000 pounds. However, it is to be understood that my invention is not limited to this value but may be adjusted to accommodate the nature of the work being erformed.

When the high pressure fluid attains a certain pre-determined value, which in actual operation materially slows down the speed of the motor I2, the pressure responsive device 90 functions and closes the contactor 96. This energizes the electro-magnet 48 and in turn, this connects the fluid pump I I from communication with the high pressure fluid portion of my system and connects it in communication with the low pressure fluid portion of my system and raises the work piston 29. Just as soon as the fluid pump is disconnected from the high pressure fluid system and connected to the low pressure fluid system, the pump immediately regains its normal speed preparatory to a succeeding stamping operation. In actual practice, the motor is of sufllcient capacity to regain its normal speed by the time that the operator has removed the piece of work from the work block and inserted a new piece of work on the work block 39, at which time the operator again manually actuates the four-way control valve 45 and connects the fluid pump again in communication with the upper side of the piston 29 in the double acting work cylinder 24 and performed another stamp stenciling, or rivetingbperation. Therefore, the complete operation of my control system is of a cyclic duty. wherein during the flrst part of the cycle the fluid pump II is connected in communication with the low pressure fluid portion of the system, which includes the volume in the double acting work cylinder 24 beneath the piston 29, and which pump, during the first part of the cycle, is driven continuously by the motor I2, which also drives a rotating mass I3, and wherein during the second part of the cycle, the fluid pump II is connected in communication with a high pressure fluid portion of the fluid system, which includes the volume in the double acting work cylinder 24 above the piston 29, and which pump during this second part of the cycle, is driven by the motor I 2 which is of insuflicient capacity to drive continuously the fluid pump II under high pressure conditions which means that the rotating mass I3 under this condition of the slowing down of the motor, supplies energy to the fluid pump to assist the motor I2 temporarily in producing a higher pressure than that which the motor I2 could produce alone, thereby completing the second part of the cycle, at which time the fluid pump .II is again reconnected in communication with the low pressure fluid portion and allows the motor I2 and the rotating mass I3 to again regain its speed preparatory to another cyclic operation.

Therefore, with my fluid system, it is possible to do relatively heavy work by utilizing a motor which is of relatively small capacity.

In Figure 2, I show an arrangement whereby my entire fluid assembly is mounted-in a housing I10 having on its front side an anvil Ill and a work cylinder support I12. In actual practice, the housing I10, the anvil HI, and the work cylinder support I12 may be cast in one integral piece, but it is to be specifically understood that the entire housing assembly and the anvil and the work, cylinder support may be constructed of separate pieces suitably connected together. As illustrated, the housing I10 is provided with a rear removable plate I13 which is fastened to the rear side of the housing I10 by means of the bolts I8I. The purpose of the rear removable plate I13 is to provide access to the inner side of the housing I10 during the assembly of my invention as well as for inspection and maintenance of the various parts after the parts-are installed and in operation.

As illustrated, the complete motor and pump assembly is mounted on top of the housing I10. The motor I14 is provided with a motor flange base I15 which is removably supported upon a major flange base I16 by means of the bolts I82. The major flange base I16 is in turn connected to the top of the housing I10 by means of the bolts I 83. The pump I is carried by a pump support I19, which support I19 is carried by the brackets I18 which are bolted to the underneath side of the major flange base I16 by means of the bolts I84. The entire motor and pump construction is arranged so that the various parts may be easily dismantled by disconnecting the various parts. Thus, the pump I80 may be removed from the pump support I19 by disconnecting the bolts I86. While I have shown the pump support. I18 as being bolted to the pump brackets I18 by means of the bolts I85, it is to be amasit understood that this pump assembly support may be cast of one integral piece. The entire motor and pump assembly may be removed from the top of the housing I18 by disconnecting the bolts I83 and lifting the entire assembly out of the housing I18. The motor I18 may in addition be separately removed by disconnecting the bolts I82 and lifting the motor from the major flange base I18. In the illustrated construction, the fly wheel I98 is carried by the motor shaft I9I, which is in turn connected to the pump shaft I92 through means of a two part coupling I93. Therefore, when the motor I18 is removed, the fly wheel is withdrawn through the opening I." in the major flange base I18.

On top of the work cylinder support I12, there is mounted a work cylinder I91 having a work piston 28I mounted therein. As illustrated, the cylinder head I98 may be suitably bolted to the top of the cylinder by means of the bolts I99. The work piston "I is adapted to be actuated by the fluid'pressure from the pump I88 and is arranged to actuate thepiston rod 282 for delivering work to the anvil I1I. In accordance with usual practice,'there is at piston packing flange 283 bolted to the lower end of the work cylinder I91 by means of the bolts 288. The entire work cylinder I91 is removably mounted on top oi" the cylinder support I12 by means of the bolts 288. The lower end of the piston rod 282 is provided with a threaded portion 288, so that a suitable piston plunger 286, which is reciprocally mounted in the cylinder support I12, may be threadably attached to the piston rod 282. In order to facilitate the assembly, the front portion of the cylinder support I12 is provided with a removable front cap 281,. which may be removably connected to the cylinder support I12 by means of the illustrated bolts 288.

The piston plunger 288 at its lower end is arranged to carry a suitable working tool which co-operates with the anvil "I for performing the working operation, such as riveting, stamping and punching. In the illustrated embodiment of my invention in Figure 2, I show an operating plunger 289 having an automatic rivet feeding device 2I8 for automatically delivering rivets to the operating plunger 289 that is actuated by the work cylinder I91. In accordance with the general construction of automatic rivet feeding device, there is provided a rivet magazine 2I I which may be suitably supported by the front cap 281. In the operation of the automatic rivet feeding device, the rivets are placed in the magazine 2 and are arranged to slide down the rivet chute 2I2 into the rivet-feeding device 2I8 which feeds the rivets one by one into the hollow end of the work plunger 289. In the drawings, a rivet 2I3 is shown in operative position just prior to the riveting operation.

Upon the anvil I1I there is mounted a work base 2I8 and may be held in position by means of the bolts 2| 9. The work base M8 is provided with a disappearing plunger 2 which is biased in its raised position by means of the plunger spring 2I5. Therefore, the first operation, when riveting the two pieces 2I8 and 2" together, is for the operator to place the two pieces 2I8 and 2I1 with the hole registering around the disappearing plunger 2 I8. Then the rivet 2 I 3 is moved downwardly by the work cylinder I91, and its lower end engages the top end of the disappearing plunger 2I8 and depresses the disappearing plunger 2, at the same time entering the registered opening in the two pieces 2 I6 and 2I1.

During the final stages of the riveting operation, the lower end of the rivet 2I3 is upset and flrmly holds the two pieces 2I8 and 2I1 together. After the riveting operation is completed. the plunger 289 is again raised by the work piston 28I, during which movement another rivet is automatically inserted into the work plunger 289 preparatory to another riveting operation. I The riveting operation is completely automatic except for the placing of the two pieces 2I8 and 2H over the disappearing plunger 2. While I have shown my invention as being operated with an automatic rivet feeding device, it is obvious that my invention may be operated with a simple riveting or other tool without any automatic arrangement.

The control valve 223 is connected by means of the bolts 222 to the Inside of the left hand wall of the housing I18 as viewed from the left side of the drawing shown in Figure 2. This control valve 223 is similar in construction to the control valve 88 as shown in Figure l of the drawings, except that the valve piston rod is actuated by two fluid cylinders 228 and 228 mounted respectively upon the right hand end and upon the left hand end of the body of the control valve 223.

The flow of the fluid to the actuating cylinder 28' and 228 is controlled by a pilot control valve 288 which is mounted upon the right hand side wall of the housing I18 as viewed from the left of the drawing in Figure 2. As illustrated, the pilot control valve 288 is provided with a flange 285 that is bolted externally of the right hand side wall of the housing I18 by means of the bolts 282. The pilot control valve is of the rotary type and has a rotary central portion288 provided with fluid ducts 281 and lu These ducts 281 and loo-operate with four spaced openings or ports for controlling the flow of the fluid to the fluid cylinders 228 and 225 which actuate the control valve 223. The rotary valve 288 is actuated by a rock shaft 283 which is suitably supported in the casing of the pilot control valve 288. The outer end of the rock shaft 283 extends externally of the casing of the pilot control valve 288 and is arranged to be manually actuated by the control handle 2. The inner end of the rock shaft 283 extends internally of the casing of the pilot control valve and is arranged to be actuated by the actuating arm 288, which is in turn controlled by a fluid pressure responsive device 228. Therefore, the pilot control valve 288 is arranged to be actuated either manually or automatically in accordance with the fluid pressure in my fluid system.

As illustrated, the pressure responsive device 228 is provided with a forward flange 233 which is externally bolted to the front of the housing I18 by means of the bolts 238. This pressure responsive device 228 is connected in communication with the high pressure portion of the fluid system and operates substantially in accordance with the same principle as the pressure responsive device 98 as shown in Figure 1 of the drawings. The pressure responsive device 229 comprises a cylinder having a piston 229 that is biased to the right by means of a spring 238. The tension of the spring 238 may be varied by the adjusting screw 23I which is mounted externally of the housing I18 and which is readily accessible for easy adjustments. When the spring adjustment is once determined, the lock nut 232 may be set to hold the adjusting screw 23! in place. li'he piston 229 actuates a piston rod 235 which in turn actuates the actuating arm 244 of the pilot control valve 246. The right hand end of the pilot piston rod 266 is provided with a slotted and elongated opening 236 into which the lower end of the actuating arm 244 is inserted.

In this embodiment of my invention, the pressure responsive device 226 takes the place of As previously explained, the motor I14 is of suflicient capacity to operate the pump I66 coni tinuously under low pressure and maintain a low the high pressure relief valve 63 shown in Figure 1 of the drawings. However, the low pressure fluid in my fluid system is controlled by a low pressure relief valve 226 which is mounted in the housing I16. The low pressure relief valve 226 is provided with an adjustment screw 221 so that the value of the low pressure fluid in my fluid system may be suitably set to accommodate any operating condition. The construction of my low pressure relief valve 226 is substantially the same as the low pressure relief valve 16 shown in Figure 1 of the drawings.

The sump 256 which holds the fluid is mounted in the base of the inside of the housing I16. The sump may be provided with a drain plug 252 mounted externally of the housing I16 to readily facilitate the draining of the fluid from the sump 256.

The operation of the fluid system shown in Figure 2 is substantially similar to the operation of the control system shown in Figure 1, except that the control valve 223 is operated by fluid pressure instead of electric or other means as shown in the other views of the drawings. In the position of the parts shown, the pilot control valve 246, has just been actuated to the low pressure position by means of the pressure responsive device 228, and fluid is being delivered to the underneath side of the work piston 26I of the work cylinder I61. Under this condition, fluid is drawn from the sump 256 through the screen 25I, the suction pipe 253, to the pump I66 after which the fluid is delivered from the pump I86 through feed pipe 254, a pilot feed pipe 263, the valve duct 241, and a pilot feed pipe 264 to the fluid actuating cylinder 224 of the control valve 223. This means that fluid is delivered to the right hand end of the control valve 223 and the piston rod of the control valve 226 is actuated to the left, and connects the feed pipe 255 in communication with the control pipe 256. When the fluid actuating cylinder 224 actuates the piston rod of the control valve 223 to the left, the fluid in the fluid actuating cylinder 225 is forced out into the sump 256, through a fluid passage including a pipe 265, the duct 246 in the pilot control valve, and a pipe 266 to the sump 256.

The flow of the fluid from the pump I66 to operate the work cylinder I61 may be described as follows: Upon leaving the pump I66, the fluid flows through a fluid feed pipe 254,-a fluid feed pipe 255 into the central inlet port of the control valve 223. From the inlet port of the control valve 223, the fluid flows through the control valve into the control pipe 256, the control pipe 251, and into the fluid duct 256 to the underneath side of the work piston 26I. Under this condition, the fluid pressure raises the work piston 26I to its upper most position as illustrated in the drawings. During its upward movement, the fluid or top of the piston 26I is exhausted to the sump 256 through the fluid duct 256, the fluid pipe 266, the fluid pipe 26I to the control valve 223, after which the fluid flows out of the control valve 223 into the exhaust pipe 262 which leads to the sump 256.

pressure sufllcient to raise the work piston 26I. as determined by the setting of the low pressure relief valve 226. When the cylinder 26I reaches the upper end of its stroke, and the pressure begins to rise above the setting of the low pressure relief valve, the fluid delivered from the pump I66 is then by-passed through the low pressure relief valve into the sump 256.

Now let it be assumed that the operator has adjusted the two pieces 2I6 and 2H over the disappearing plunger 2 and is ready to perform another riveting operation. To do this}. the operator merely actuates the pilot control handle 24I downwardly in a counter-clockwise direction. Under this position of the pilot control valve 246, the fluid in the feed pipe 254 and the pilot feed pipe 266 is connected in communication through the valve duct 246 to the pilot pipe 265 which is connected to the left hand end of the control valve 223 to the fluid actuating cylinder 225. This causes a fluid pressure to actuate the control valve 223 to the right and at the same time causes the fluid in the fluid actuating cylinder 224 on the right hand end-of the control valve to be expelled to the sump 256, through the pipe 264, the fluid duct 241 of the pilot control valve and through the pipe 266 to the sump 256. When the control valve 223 is actuated to the right, the fluid which flows into the inlet port is now connected in communication with the control pipes 26I and 266, and the fluid duct 259 to the upper side of the work piston 26I. This causes the work piston to move downwardly and forces the fluid on the underneath side of the work piston 26I to the sump 256, through the fluid duct 256, the fluid pipe 251, the pipe 256 to the control valve 226, after which the fluid is delivered to the exhaust pipe 262 to the sump 256.

When the work piston 26I reaches the low end of its stroke and is doing heavy work to upset the rivet, the pressure, of the fluid builds up to a relatively high value, until it reaches the setting of the pressure responsive device 226. Just as soon as the pressure builds up to this setting, the fluid which flows through the pipe 261 to the pressure responsive device 226 forces the piston 226 to the left and compresses the spring 236. The movement of the piston 226 to the left causes the piston rod 235 to actuate the actuating arm 244 in a clockwise direction and move the pilot control valve 246 again to its low pressure position. Just as soon as the pilot control valve 246 is moved to its low pressure position, the pressure of the fluid operating against the piston 229 of the pressure responsive device 236' is again lowered to its low pressure value as determined by the low pressure relief valve 226, and the spring 236 actuates the piston rod 265 to the right, but the actuating arm 244 remains in its low pressure position, being the position shown in Figure 2 of the drawings.

When the fluid pump I66 is connected in communication with the upper side of the work piston 26I and is doing heavy work, the motor is of insuiflcient capacity to drive continuously the pump. However, just as soon as the motor I14 begins to slow down, the revolving fly wheel I66 delivers energy to the pump I66 and assists the motor I14 in building up a higher pressure than that which would normally be created in the absence of the revolving fly wheel I66. In

the operation of my device for extraordinarily heavy work the setting of the adjusting screw 23I of the pressure responsive device 228 is such that the spring tension is arranged to be overcome by the fluid pressure acting against the piston 229 when the motor I14 and the flywheel I98 begins to slow down materially. In other words, the maximum amount of energy is delivered out of the motor I14 and the fly wheel I98 before the pressure responsive device 228 operates to shift the pilot control valve 248 to its low pressure position. For relatively light work, the setting of the adjusting screw 23I may be relatively low because there is no need for a high pressure being exerted on the work. In this case the motor may not slow down very much before the pressure responsive device 228 operates to actuate the pilot control valve 248. Just as soon as the pilot control valve 248 is actuated to its low pressure position, the motor I14 again resumes its speed and is ready for another operation, by the time that the operator has inserted new pieces of work upon the anvil I1I. In my invention the motor I14 may be relatively small and still, by means of the rotating fly wheel I98, deliver a relatively high fluid pressure for doing considerably heavy work for riveting or other similar operations. In this manner, the over-all size and weight of the combined unit is materially reduced and the entire assembly may be positioned upon a suitable work bench where it is handy for the operator to operate it.

In Figure 3, I show a modified arrangement of the invention shown in Figure 2, in that the valve piston rod 216 of the control valve 218 is actuated manually in one direction by the control handle 286 and actuated in the other direction by the pressure responsive device 381. In Figures 2 and 3, like parts of the invention are designated by like reference characters. Another main distinction between the invention shown in Figure 2 and in Figure 3 is that in Figure 3, the entire control assembly is suspended from the fluid pump I88. By means of this construction, the entire assembly including the motor I14, the fly-wheel I98, the pump I88, the control valve 218, the pressure responsive device 381, the low pressure relief valve 226, and the connecting pipes may be bodily removed by lifting the entire assembly through the opening in the top of the housing I18. To do this, it is only necessary to disconnect the two control pipes 3I9 and 328 by loosening the connecting nuts 3I3 and 3M, respectively, and bend the two pipes which are in actual construction made of bendable tubing, so as to clear the opening in the upper end of the housing I18. As is observed, in the drawings, all of the other mounted parts will clear the opening in the upper end of the housing I18 as they are lifted from the housing I18. Also preparatory to lifting the entire assembly out of the housing I18, the manually operated handle 286 and the external flange 281 must be disconnected. After the handle 286 is removed, the flange 281 may be removed by disconnecting the bolts 288. In accordance with the usual construction, the flange 281' is provided with a bearing for supporting an actuating shaft 285 that is actuated by the manual control lever 286. There is a relatively large opening 298 in the side of the housing I18 to make room for the bearing portion of the flange 281. This means that when the flange 281 is removed, there is a considerably large space around the shaft 285, so that the entire assembly may be tilted sufilciently to allow the shaft 285 to clear the inside of the housing as the entire assembly is being lifted out of the upper end of the housing I18.

The control valve 218 is constructed substantially like the control valve 45 shown in Figure 1 of the drawings, except that the upper end 28I vided an extension bracket 2" for supporting the control valve 218. The upper end of the extension bracket 21I may be bolted to the lower end of the fluid purnp- I88 by means of the bolts 212. The lower end of the extension bracket 21I is provided with an extension plate 213 which may be bolted thereto by means of the bolts 214. The upper end of the control valve 218 is bolted directly to the suspension plate 213 by means of the bolts 215. By means of this construction, the control valve 218 is rigidly suspended from the fluid pump I88.

As illustrated, the valve piston rod 216 of the control valve 218 is somewhat reduced at its upper end as indicated by the reference character 211 and extends externally of the control valve 218 and above the suspension plate 213 for manual and external actuation by means of the manual control lever 286 and the control arm 284. In this embodiment of my invention, the control arm 284 is non-rotatively mounted to the control shaft 285. When the manual control lever 286 is actuated downwardly, the control arm 284, in turn, actuates the valve piston rod 286 downwardly to transfer the fluid connection for actuating the work piston 28I. The downward movement of the valve piston rod 216 is opposed by a spring 218 which urges the valve piston rod 216 to its upper most position. The lower end of the spring 218 engages a shoulder portion upon the upper end of the body of the control valve 218 and the upper end of the spring 218 engages a spring washer 219 which is fastened to the control valve piston rod 216 by means of a pin 288. Consequently, the action of the spring 218 is such as to urge the control valve piston rod 216 to its uppermost position.

As shown the lower end 282 of the control valve 218 is provided with a locking arrangement to hold the control valve piston rod 216 in its lowermost position against the biasing action of the spring 218 until the pressure responsive device 381 is actuated to release the locking arrangement. This locking arrangement includes a bushing 292, a movable sleeve 294 that slides up and down relative to the bushing 292, and two oppositely disposed balls 295 mounted in oppositely disposed openings in the bushing 292. The upper end of thebushing 292 is provided with a flange portion 293 which secures the bushing 292 stationary with respect to the body of the control valve 218 when the lower end of the control valve 282 is attached to the lower end of the body of the control valve 218.' The lower end of the control valve piston rod 218 is somewhat reduced as indicated by the reference character 289 and is arranged to slide up and down in the longitudinal opening of the bushing 292. Also as illustrated, the reduced end 289 of the control valve piston rod 216 is provided with a circumferential groove 290, which, when the control valve piston rod 216 is actuated downwardly by the manual control lever 286, is engaged on opposite sides by the two balls 295 which are forced inwardly by the action of the spring 291 urging the movable sleeve downwardly and causing the sloping sides of the ball recesses 296 to force the two balls in to the circumferential groove 290. As the two balls 295 are forced into the circumferentialgroove 290, the spring 291 continues to urge the sleeve 294 downwardly until the right hand end of the pivot control lever 302 engages the bottom of the slot 30I in the lower end of the external actuating plunger 3I0 of the pressure responsive device 301. In this lower'position of the movable sleeve 294. the two balls 295 are locked into the circumferential groove 290 because in this position, the two balls 295 engage the internal diameter of the movable sleeve 294. As the external actuating plunger 3I0 is raised by the high pressure fluid of the fluid system, the right hand end of the pivot control lever 302 is raised, which in turn, raises the movable sleeve 294 and the two balls 295 are allowed to move outwardly into the two ball recesses 296. When the two balls 295 are allowed to move outwardly into the two ball recesses 296, the upwardly urging force of the spring 218 in the upper end of the control valve 210 causes the control valve piston rod 216 to move upwardly to the position as shown in the drawings. The left hand end of the pivot control lever 302 may be pivoted to a pivot bearing 303 carried by the extension provided on the lower end of the control valve 282. The intermediate portion of the pivot control lever 302 may be pivotally connected to the movable sleeve 294 by means of a pivot pin 304.

The pressure responsive device 301 is constructed substantially like the pressure responsive device 228 shown in Figure 2 of the drawings and is provided with the adjustment screw 308 which may be locked in position by means of a lock nut 309. The adjustment screw 308 is similar to the adjustment screw 23I of Figure 2. Any suitable means may be used to support the pressure responsive device and as illustrated, it may be suitably bolted to the side of the control valve 210 by means of the bolts 306. The large rear plate 3 in Figure 3 is similar to the large plate I13 in Figure 2, except that the plate 3 is provided with a small inspection plate 3 I 2 which may be suitably bolted to the large plate 3I I.

The operation of the assembly shown in Figure 3, so far as the flow of the fluid to the work piston 20I is concerned, is substantially like that described with reference to Figure 2. Briefly, the fluid is sucked through the screen 3I1 into the suction pipe 3I6 to the fluid pump I 80. In this embodiment of my invention, the fluid is poured directly into the housing I and surround the control valve 210 and the other associated parts. The lever of the fluid may be as high as the top of the pressure responsive device 301. However, it may be higher than the pressure responsive device 301 but it would be rather inconvenient to adjust the setting of the adjustment screw 308 if it were immersed in the fluid. After the fluid is delivered to the fluid pump I80 it flows through a pipe 3I8 into the central portion of the control valve 210, from thence in ac cordance with the position of the valve as shown in the drawings, the fluid flows out of the control valve 210 into the control pipe 320 and raises the work piston 20I in the position as shown in the drawings. During the time that the work piston 20I is being raised, the'fiuid above the piston was forced out through the duct 259, the pipe 3I9, through the control valve 210 where the fluid is then exhausted directly to the reservoir in the housing I10, through the exhaust port 322. As previously pointed out, this position is referred to as the low-pressure position and when the fluid has raised the work piston 20I to its uppermost position, the excess fluid then is allowed to escape through the low pressure relief valve 226 to the fluid reservoir in the housing I10.

Now let it be'assumed that the operator actuates the manual control lever 286 downwardly and depresses the control valve piston rod 216 until it is locked by means of the two balls 295 in its lowermost position as previously described. In this position of the control valve, the fluid flowing from the pump I80 through the pipe 3I8, is connected in communication through the control valve 210 and to the control pipe 3| 9, whereupon the fluid flows through the duct 259 and causes the work piston 22I to be actuated downwardly. The downward movement of the work piston 20I causes the work tool 269 to engage the work which may be placed between the work tool 269 and the anvil I1I. As the work piston 20I is moved downwardly, the fluid thereunder is forced out through the duct 258, the pipe 320, and the low pressure relief valve 226 to the fluid reservoir in the housing I10. When the work piston 20I moves downwardly and the work tool 269 engages the work upon the anvil I1I, the pressure of the fluid immediately rises to a high value and causes the fluid in the pipe 32I which leads to the pressure responsive device 301 to raise the piston therein and cause the external actuating plunger 3I0 to lift the right hand end of the pivot lever 302 and raise the movable sleeve 294 to unlatch or unlock the control of piston rod 201 by allowing the two balls 295 to move out into the two ball recesses 295. Just as soon as the control valve piston rod 216 is unlocked, the spring 218 upon the upper end of the control valve 210 urges the control valve piston rod upwardly to the position shown in the drawings, whereupon the piston is preparatory to begin another work cycle upon the downward movement of the manual control lever 286.

The fluid in the housing I10 may be drained through the plug 3I5. Also in this embodiment of my invention, the over-all size and weight of the combined unit may be such that the unit may be positioned upon a suitable work bench where it is handy for the operator to operate it.

It is to be observed that throughout all of the forms of my invention, the motor is of sumcient capacity to drive the pump continuously when the pump is connected in communication with the low pressure fluid portion of my system, and further, that during the period that the motor is slowing down, it is observed that the rotating fly wheel delivers energy to assist the motor in driving the pump to produce a higher pressure than that which would be normally produced by the motor alone, and still further, that the action of the pressure responsive device is such that the pump is disconnected from the high pressure fluid portion of a system and con- ,nected to the low pressure fluid portion of the system at the point somewhat before the motor is completely stalled. Also, the operation of my fluid system is such that it gives very delicate operation. Thus, I find that it may be used to rivet composition material together, or to rivet composition material to metal material without cracking or damaging the composition material by excess pressure of the working tool or plunger. This is because of the critical control made possible by the combination of the fluid pressure responsive device which shifts the system from a high pressure system to a low pressure system, taken together with the drooping power characteristic of the motor and the fly wheel when operating under the high pressure condition. This combination is such that the nature of the riveting action can be definitely controlled to give the desired work pressure under any diflicult work condition.

Although I have described my invention with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

I claim as my invention:

1. A self-contained fluid work device having a high pressure fluid portion and a low pressure fluid portion comprising, in combination, a housing having an opening at the top, an anvil externally carried by the housing, a support externally carried by the housing and positioned above the anvil, a fluid work cylinder and piston supported by the said support, a work plunger operated by the piston and arranged to move relative to the anvil, means in the housing for connecting the work cylinder in communication with the high and low pressure fluid portions, a fluid pump mounted in the housing for delivering a fluid to the high and low pressure fluid portions,.a motor mounted on the housing for driving the pump, control means mounted in the housing for alternately connecting the pump in communication with the high and low pressure fluid portions to operate reciprocally the said piston relative to the anvil, a fluid pressure responsive device in the housing connected in communication with the high pressure fluid portion of the fluid system, manual means extending externally of the housing for actuating the control means to one operating position, locking means for locking the control means in said operating position, resilient means for urging the control means in another operating position, and a fluid pressure responsive device in the housing for releasing the locking means to cause the resilient means to urge the control means to the said another operating position, a flange mounted on top, and extending over the opening, of the housing, means for mounting the motor on top of the flange, and means within the housing for suspending the other associated parts, including the fluid pump, the control means, and the fluid pressure responsive device from the flange.

2. A self-contained fluid work device having a high pressure fluid portion and a low pressure fluid portion comprising, in combination, a housing, having an opening at the top, an anvil externally carried by the housing, a support externally carried by the housing and positioned above the anvil, a fluid work cylinder and piston supported by the said support, a work plunger operated by the piston and arranged to move relative to the anvil, means including fluid conduits within the housing for connecting the Work cylinder in communication with the high and low pressure fluid portions, a fluid pump mounted in the housing for delivering a fluid to the high and low pressure fluid portions, a

motor externally mounted on the housing for driving the pump, control means mounted in the housing for alternately connecting the pump in communication with the high and low pressure fluid portions to operate reciprocally the said piston relative to the anvil, a fluid pressure responsive device connected in communication with the high pressure fluid portion of the fluid system, means for causing the fluid pressure responsive device to govern the control means, manual means extending externally of the housing for actuating the control means, a flange mounted on top, and extending over the opening, of the housing, means for mounting the motor on top of the flange, and means within the housing for suspending the other associated parts, including the fluid pump, the control means, and the fluid pressure responsive device from the flange.

3. A self-contained fluid work device comprising, in combination, a housing having an opening at its top and flange means embracing same, a fluid work cylinder and piston externally supported by the housing, a work portion externally supported by the housing and arranged in a work position relative to the piston, a fluid pump mounted in the housing and suspended from the flange means, a motor mounted on the flange means externally of the housing for driving the pump, control means carried by the flange means in the housing for alternately connecting the pump in communication with the cylinder on opposite sides of the piston to reciprocally operate the piston relative to the work portion, pressure relief means carried by the flange means in the housing to relieve the pressure of the fluid on one side of the piston, said motor being of suflicient capacity to drive continuously the fluid pump when connected in communication with the cylinder on the relieved pressure side of the piston and of insuflicient capacity to drive continuously the fluid pump when connected in communication with the cylinder on the other side of the piston, a rotating mass mounted in the housing and driven by the power means and adapted to assist the motor to drive the pump when connected in communication with the cylinder on said other side of the piston, pressure means carried by the flange means in the housing and responsive to the pressure of the fluid in the cylinder on said other side of the piston for actuating the control means in one direction to connect the pump in communication with the cylinder on the relieved pressure side of the piston, and means externally of and extending through the housing to actuate the control means in the opposite direction to connect the fluid pump in communictaion with the cylinder on the relieved pressure side of the piston.

4. A self-contained fluid work device comprising, in combination, a housing having an opening, a fluid work cylinder and piston externally supported on the housing, a work portion externally supported on the housing and arranged in a work position relative to the piston, a motor, a pump driven by the motor, control means for governing the flow of fluid between the pump and the work cylinder to reciprocally operate the piston relative to the work portion, and removable flange means embracing the said opening for mounting the pump, the control means and the motor as a unit upon the housing.

5. A self-contained fluid work device comprising, in combination, a housing having an opening, a fluid work cylinder and piston externally supported on the housing, a work portion externally supported on the housing and arranged in a work position relative to the piston, flange ing, a fluid work cylinder and a piston externally supported on the housing, a work portion externally supported on the housing and arranged in a work position relative to the piston, a motor, a fluid pump driven by the motor, means including fluid conduits in the housing connecting the pump in fluid communication with the work cylinder, control means in the housing connected with the fluid conduits for governing the flow of the fluid between the pump and the work cylinder to reciprocally operate the piston relative to work portion, means extending externally of the housing for operating the control means, removable flange means embracing the said opening, means for externally mounting the motor on the flange means, and means for internally supporting the pump and the control means in the housing from the flange means.

7. A self-contained fluid work device comprising, in combination, a housing having an opening, a fluid work cylinder and a piston externally supported on the housing, a work portion externally supported on the housing and arranged in a work position relative to the piston, a motor, a fluid pump and a rotary mass driven by the 'motor, meansincluding fluid conduits in the housing connecting the pump in fluid communication with the work cylinder, control means in the housing connected with the fluid conduits for governing the flow of the fluid between the pump and the work cylinder to reciprocally operate the piston relative to the work portion, means extending externally of the housing for operating the control means, removable flange means embracing the said opening, means for externally mounting the motor on the flange means, and means for internally supporting the rotating mass,-the pump and'the control means in the housing from the flange means.

8. A self-contained fluid work device comprising, in combination, a housing having an opening, a fluid work cylinder and a piston externally supported on the housing, a work portion externally supported on the housing and arranged in a work position relative to the piston, a motor,

a fluid. pump and a rotary mass driven by the motor, means including fluid conduits in the housing connecting the pump in fluid communication with the work cylinder, control means in the housing connected with the fluid conduits for governing the flow of the fluid between the pump and the work cylinder to reciprocally operate the piston relative to the work portion, means extending externally of the housing for operating the control means, removable flange means embracing the said opening, means for externally mounting the motor on the flange means, and means for internally supporting the rotating mass, the pump and the control means in the order named in the housing from the flange means.

- JOHN C.'COTNER. 

